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Synthesis of Pyrrole Derivatives through Functionalization of 3,4‐Bis(lithiomethyl)dihydropyrroles
Author(s) -
Barluenga José,
Fañanás Francisco J.,
Sanz Roberto,
Ignacio José M.
Publication year - 2003
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200390120
Subject(s) - chemistry , electrophile , nucleophile , pyrrole , intramolecular force , surface modification , combinatorial chemistry , bicyclic molecule , derivative (finance) , organic chemistry , medicinal chemistry , catalysis , financial economics , economics
Bis(2‐lithioallyl)amines 2 , substituted at the double bonds, undergo intramolecular carbolithiation of a lithiated double bond in different solvents to afford dilithiated dihydropyrroles 3 . Treatment of these dianions with electrophiles allows the preparation of functionalized pyrrole derivatives 5 and 6 . Interestingly, treatment of these dianions with carboxylic esters selectively affords either keto or hydroxy compounds ( 9 or 10 ), depending on the conditions. Several experiments have been carried out in order to clarify the mechanism of this selective transformation. Finally, dilithiated dihydropyrrole 3a could be transformed in a three‐step procedure into the corresponding 3,4‐bis(bromomethyl) derivative 31 , which can easily be converted into bicyclic pyrrole compounds 32−33 by treatment with different nucleophiles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)